Helsinki Pride will go on as planned, according to the event organisation's chair Panu Mäenpää.
He made the comments on Monday on Yle TV's breakfast show, adding that security plans will be reviewed with authorities starting on Monday.
Mäenpää said that organisers and staff discussed the matter on Saturday after the attack in the centre of Oslo early that morning.
A 42-year-old Norwegian man was arrested and charged with murder, attempted murder, and committing terrorist acts. Norwegian police described it as an "act of Islamist terrorism" while adding that the suspect has had "mental health challenges".
Oslo Pride cancelled a parade scheduled for Saturday due to the attack, but Mäenpää said that the Helsinki Pride organisers considered it important to continue as intended.
"If we go back now, we will give power to the hatred shown by the act of terrorism. That's why it was felt that now it is as important as ever that our voice is heard loud and clear," Mäenpää said.
Helsinki Pride is a human rights and cultural event that aims to protect the equality of all people, regardless of sexual orientation or gender identity.
Pride Week takes place from June 27 to July 3, while Pride Month began on June 1.
In total, more than a hundred events have been planned, including lectures, seminars and exhibitions. The culmination will be Saturday's parade, in which more than 100,000 people had participated annually before the Covid pandemic.
Jenni Haukio, wife of President Sauli Niinistö, is the event's matron this year, following in the footsteps of Prime Minister Sanna Marin (SDP) who served in the role in 2020.